The use of solvents, such as hydrocarbons and chlorinated hydrocarbons, is well known in the dry cleaning art. It is also known to impart water repellency to fabrics and leathers by applying thereto various silicone fluid and resin compositions. Thus, for example, in U.S. Pat. No. 2,672,455, Currie teaches a composition of matter comprising a hydrolyzable titanate ester, a methyl polysiloxane copolymer composed of trimethylsiloxane units and SiO.sub.2 units, said units being in such proportion that the ratio of methyl radicals to silicon atoms is from 1.0:1 to 2.5:1, and a polysiloxane (generally a polydimethylsiloxane fluid). Solutions of such compositions were used by Currie to impregnate leather in order to produce a water-repellent surface. Similar compositions were later used in the art to treat various fabrics to achieve waterproofing character thereon.
Solvent and silicone combinations have been employed in the art to simultaneously clean and waterproof (protect) fabrics and other surfaces. By way of example, in U.S. Pat. No. 3,123,494, Charreau discloses a process for dry cleaning contaminated textile articles with a composition comprising a solvent, selected from hydrocarbons or chlorinated hydrocarbons, a methylpolysiloxane waterproofing agent and an alkyl titanate. The methylpolysiloxane in this case is preferably selected from dimethyl polysiloxane resins or methylhydrogen polysiloxane resins, said resins being mixed with at least one fluid selected from liquid dimethyl polysiloxane or liquid methyl hydrogen polysiloxane. The process comprises immersing a contaminated textile in said composition, agitating the textile sufficiently to cause foam formation, separating the thus cleaned textile from the composition and foam, removing adherent solvent and drying the textile, thereby retaining from 2 to 3 percent of said methylpolysiloxane on the textile, which imparts the waterproofing character. In this instance, improved cleaning action was believed to result from foam generated in the solvent by inclusion of the methylpolysiloxane.
In a more recent disclosure, U.S. Pat. No. 4,501,682, Goodman et al. teaches a cleaning and protective composition consisting of an admixture of poly(methyl-hydrosiloxane), tin octoate and zinc octoate in at least one solvent. The solvent in this case is selected from cyclic or linear polydimethylsiloxanes, petroleum distillates, methylene chloride, or mixtures thereof.
Kasprzak, in a copending application, Ser. No. 670,195, filed Nov. 13, 1984 and assigned to the assignee of the present invention, has shown that perchloroethylene can be combined with cyclic dimethyl siloxanes to produce synergistic cleaning effects in removing stains of oil, grease or sebum from textiles.
Although the cleaning compositions comprising various solvents and the waterproofing compositions comprising siloxane resins perform their respective functions effectively when applied separately (or sequentially), there is still a need for an improved composition which would combine the cleaning and waterproofing results. Such combination of the cleaning and waterproofing functions in one composition is desirable since the number of steps required to perform both operations is reduced. Thus, for example, when compositions similar to those described by Charreau, supra, are applied to a fabric having an oil or grease stain thereon, inadequate cleaning of the stain is observed.
It has now been found that, over a certain composition range, inclusion of a relatively small amount of a siliconeoxyalkylene copolymer in a composition comprising a siloxane resin copolymer, a polydimethylsiloxane fluid, a titanate es ter and a volatile cyclic polydimethylsiloxane, provides significant improvement with respect to stain removal while still imparting good water repellency to a fabric treated therewith.